The leisure group, which also runs Costa coffee shops, has emerged as a beneficiary of the credit crunch as Britons find ways to economise on travel and eating out. The shares jumped 6% to £11.88 in early trading and later traded up 37p at £11.57, a rise of 3.3%.

The Premier Inn budget hotel chain, which accounts for the bulk of Whitbread's profits, has outperformed the wider hotel market, with like-for-like sales up 10.2%. The 570-strong hotel chain is on track to open more than 4,000 new rooms this year.

Alan Parker, the chief executive, said Premier Inn is increasingly attracting business customers as companies cut their travel budgets amid fears that the economy is sliding into recession. "Large companies realise they have to save money," he said. "Why pay more than £100 to stay in a four-star hotel when you can pay £50?"

Business travellers now make up 60% of Premier Inn sales in cash terms, with leisure travellers accounting for the remaining 40%. Business customers tend to stay two nights and spend more while leisure travellers usually stay one night. Leisure bookings slowed in June and July, though August was strong.

Paul Hickman at KBC Peel Hunt said Premier Inn is "currently enjoying an 'Aldi effect' through corporate buyers' cost-cutting, though we feel this may be overtaken by headwinds in 2009 as unemployment rises".

Like-for-like sales across the group climbed by 7% in the 24 weeks to August 14.

The pub restaurants increased their sales by 4.4% after the company introduced new menus - including more cheap deals - and revamped its restaurants. Brewers Fayre has a special offer of two meals for £9 during the day, which has been very popular. Covers at the pub restaurants are up 9.3%. KBC's Hickman said this strong growth suggests "energetic promotion activity, which will have a margin effect".

The group reiterated it remained "vigilant in these challenging economic times and alert to whatever further action is required".

Faced with soaring food and energy inflation, Whitbread has implemented a £25m cost-saving programme, which involved bringing the hotel and restaurant management teams together. It has also made changes to staff scheduling.

Like-for-like sales at the 1,100-outlet Costa chain rose by 3.7%, slower than the 6% growth experienced in the first quarter. Total sales surged 23.6%, driven by Costa's rapid expansion - it now has 331 cafes overseas. It opened in Beijing ahead of the Olympics and now has 30 outlets in China plus a handful in Russia.

"There are no obvious signs to date that the business is being affected by the weakening economic environment," said Sam Hart at Charles Stanley stockbrokers.